Evaluation of Vitreous Carbon Tooth-Root Implants (Vitredent design) in baboons will continue until all implants have been at risk for five years (1979). In conjunction with researchers from the bioengineering department of the Rensselaer Polytechnic Institute, measured stresses will be applied to a selected number of these implants and the pattern of implant deflection traced. Evaluation of the safety and efficacy of the Vitredent implants in humans will continue; ultimately 50 implants will be placed and restored in these clinical trials, involving mandibular single interdental and distal abutment applications of this implant. Histologic evaluation of nonfunctional rods of five materials placed subgingivally in edentulous areas of Vervit monkeys will be carried out; comparisons will be made between tight and loose fitting rods.